This section provides background information related to the present disclosure which is not necessarily prior art.
In general, an airbag module is a device to protect an occupant in a vehicle by absorbing physical impact, which is caused upon vehicle collision, through the elasticity of an airbag cushion. The airbag module is installed at each part of the vehicle according to the need, and classified into a driver airbag module to protect a driver, a passenger airbag module to protect an occupant seated at a passenger seat, a curtain airbag module mounted along a roof rail to protect the side of an occupant, and a knee airbag module installed in an instrumental panel to protect the knee of the occupant.
Hereinafter, the deployment procedure of a knee airbag according to the related art will be described with reference to FIG. 1.
As shown in FIG. 1, when an inflator 11 is operated, an airbag cushion 10 of a low mounting knee airbag module is deployed in a lower direction (toward the floor inside a vehicle) and then laterally deployed toward the shin of the occupant. Thereafter, after the airbag cushion 10 moves up along the shin of the occupant, the deployment of the airbag cushion 10 has been normally finished.
However, since the airbag cushion 10 according to the related art strikes the shin of the occupant as described above, the shin of the occupant, which is weaker for the impact than the knee of the occupant, is injured. In addition, since the airbag cushion 10 strikes the shin of the occupant and then is deployed upwardly, the airbag cushion 10 may be not deployed rapidly.
Accordingly, the technology of a knee airbag cushion more rapidly deployed upwardly to stably the knee of the occupant must be developed.